The moisture-dependent physical properties of agricultural grains are important to design post
harvest equipments of the product. In the current study, various physical properties of two different paddy
cultivars were determined at five moisture content levels of 8, 11, 14, 18 and 21% (d.b.). In the case of
Alikazemi cultivar, the average length, width, thickness, equivalent diameter, surface area, volume, sphericity,
thousand grain mass and angle of repose increased from 9.83 to 10.05 mm, 2.65 to 2.76 mm, 1.92 to 2.01 mm,
3.72 to 3.85 mm, 39.37 to 42.12 mm2, 26.91 to 29.94 mm3, 37.51 to 38.04%, 27.63 to 31.20 g and 35.67º to
41.23º, respectively, as the moisture content increased from 8 to 21% (d.b.). The corresponding values
increased from 10.20 to 10.25 mm, 2.31 to 2.40 mm, 1.85 to 1.92 mm, 3.53 to 3.63 mm, 36.87 to 38.61 mm2,
23.12 to 25.11 mm3, 34.53 to 35.27%, 24.43 to 27.80 g and 38.27º to 44.37º, respectively, for Hashemi cultivar.
For Alikazemi cultivar, the static coefficient of friction of grains increased linearly against three various
surfaces, namely, glass (0.3168-0.4369), galvanized iron sheet (0.4179-0.4965), and plywood (0.4394-0.5264)
as the moisture content increased from 8 to 21% (d.b.). The corresponding value for Hashemi cultivar increased
from 0.3577 to 0.4650, 0.4629 to 0.5082 and 0.4857 to 0.5452, respectively, against three mentioned surfaces.